Mechanical refrigeration is subject to unpredictable failure and requires periodic maintenance. Consequently, there are shut-downs of refrigeration equipment which cannot be avoided from time to time, it being shut-downs which are acceptable with the invention as it is herein disclosed for use in situations where interruption in refrigeration cannot be tolerated. For example, a near freezing or extremely low temperature must be maintained without failure in certain methods and processes; such as in the preservation of cadavers and embalming processes therefor involving solutions at freezing temperature. It is a general object of this invention to provide for continuity in the prolonged application of said near freezing or extremely low temperature to methods and processes which cannot tolerate interruptions and/or variation in the withdrawal of heat.
The logistics of the present invention is to provide duplication of the basic refrigeration system with controls therefor, by which a primary system may be shut down automatically and the other secondary system put into operation in lieu thereof. The transfer of operation from the primary system to the secondary system is automatic in response to sensors in the major system functions, while the transfer from secondary to primary is manual. In practice, there are manual transfer switches for deliberate manipulation of the controls and selective operation of either system, and there are pressure operated switches that respond to such functions as (1) excessive system pressure, (2) loss of refrigerant, and (3) loss of heat transfer media; for automatic protection of each system. Each of the two systems has its sensors responsive to these functions. In practice, therefore, the primary system is the normally operable system and in the event of a failure or abnormal condition therein affecting the aforesaid functions (1-3) there is an automatic transfer of operation to the other or alternate secondary system. As will be described, there are distinguishable indicator lights and an alarm to warn of the malfunction of the one primary system and automatic transfer of operation to the other secondary system.
The dual refrigeration system employed herein for the processing of cadavers and the like involves a tank or vat in which the processed body is immersed into a low temperature solution that remains fluid by virtue of its low freezing point. The vat walls transfer the heat into a heat transfer media such as water-glycol, and in practice the vat is double walled so that the heat transfer media has coextensive contact with the inner wall of the vat, the outer wall being insulated.